#/bin/bash

# read num
# flg=0
# i=2
# while(($i<$num))
# do
#     if(($num%i==0)); then
#         let flg++
#         break
#     fi
#     let i++
# done

# if(($flg==0)); then 
#     echo "$num是一个素数"
# fi

# days=('星期一','星期二','星期三')
# for i in {0..2}
# do
#     echo $((days[i]))
# done 


read a 
read b
read c

result=0
if (($c=='+')); then 
    result=$((a+b))
fi 

echo $result